Tube-mill.



W. FENNELL.

TUBE MILL.

APPLICATION FILED JUNE 12, 1913.

PatentedSept. 28,1915.

W M XVGOG, 5000M G 7500 @060 S @0609 X f f WILLIhm' FENNELL, or scores-3e,

areas sneer, sin-memo.

ahaaia mn ammu- Application filed June 12, rate,

To all whom it may, concern:

Be it known that 1., WILLIAM FENNELL, a, subject of the King ;of Great Britain and Ireland, residing at Southain, near Rugby, in, the county of Warwick, England, have invented Improvements in or Relating to Tube-lvlills, of which the following is a specification. i v In the specification of another application forlLett'ers Patent filedby ,nie' November 'l'6th 1912, Serial No; $31861, l have described. the use iii-tube mills for grinding and pulverizingfcement, slagylirnestone, ore,

coal and'other mamriale of "a'large number of loose freelymovable grinding bodies each made hollow or partly hollow for the reception and movement of material to be ground and made of comparatively small length in relation to-the diameter of the mill but oi greater length than diameter or Width, the

relative dimensions and shape being such that the. several grinding bodies when in use will not roll uponeach other but will move in planes'at right angles, or approximately so, to the axis of the rotatin mill and will raisernaterial to be'ground trom the lower part of the mill and distribute it among the grinding bodies, all as and for the purposes set forth in the said specification.

In the said former specification, the grinding bodies described by way of example, comprised short bodies of circular,

oval or elliptical shape in cross section and haying a. hole extending centrally and lengthwise therethrough, their length being equal to only a small fraction of'theradius of the mill. Now according to the present invention, the comparatively small clongated hollow grinding bodies are each formed with one ormore grooves, recesses, holes or passages (hereinafter referred to generically as holes) extending from its exterior surface inward to any desired extent .but preferably [sofas to pass completely through the wall of the hollow body and communicate with the hole or passage ea. tending lengthwise therethrough. In either case the weight of the grinding body relatively to its overall dimension will, with advantage, be decreased as compared with the grinding bodies described in the said former specification. The holes may be of any dee pcoiilcetioa of letters Pateht.

-tilbe ti having a number through its wall.

Patented Sept. 2%, 1M5. Serial a name.

sired shape, as for'exaniple circular or slotlike, andin the latter case may be curved ,or straight and be example at right angles or inclined to the axis of the grinding body. The unrecessed or unperforated portion or portions of the outer surface of the grinding bodies must of course'he Wider or larger than the recessed or perforated portion or portions thereof so as to avoid. any possibility of adjacent grind ing bodies becoming interlocked or entangled With each other instead of sliding endwise one against the other. a

Grinding bodies such as described may be of hardened and tempered steel or of other metal or material according to the nature of the material to be ground.

In the accompanying illustrative drawlegs, "Figure shows in central longitudinal section, and Fig. 2 in cross section, to a larger scale, a tube. mill, Figs. 3 and l show respectively in side elevation and vertical section, one of the improved grinding'bodies. Fig-5 shows a perforated metal; strip from which grinding bodies such as shown in Figs. 3 and 4 can coilveniently be made. Fig. 6 shows in end view a modified form of the grinding body."

' 1 is a tube mill of any ordinary construe tion having hollow trunnions 2 and in which a large number of loose freely morale grinding bodies constructed according to the present invention, with intermixed cement or other material to be ground, are placed for the purpose of grinding such cement or other material when the mill is rotated, the mass of grinding bodies, with intermixed material being indicated at 3 and bounded at the top by the dotted line 3.

Figs. 3 and i show a hollow grinding: body made in the Form of a short cylindrical of holes extending Such holes may be elongated and inclined to the axis of thehcllow body, as shown at 'T in Figs. 3, land 5,01 be, arranged at right angles to the aXis of the; body as shown at El in. Fig. 5, or be made of curved form, for example of circular form. as shown at 9 in Fig. 5. Such hollow perforated. grinding bodies may conveniently be inadeirom' strip metal 10, for examr. (see Fig 5), in which the holes variously arranged, as for 1 lllt iii

sired shape are punched and which is then cut into short lengths or blanks that are bent into tubular shape in any convenient man- .ner to form the required hollow perforated grinding bodies. The grinding bodies instead of being of circular cross section, as shown in l, may each be of other shape in end view or cross section, for example of hollow, oval shape as shown in Fig. 6. The

. over at the top of the load and descending and also turning over end for end when they abut endwise againsteach otherv until they reach the bottom of the mill when they again ascend. In this way the bodies slide endwise against each other and grinding Cir material between them. The holes or passages '7, 8, 9 (Figsfi, l. and 5) extending through the walls of each body serve in addition to the hole 11 extending throughthe center of the body, to further lighten the body as compared with its overall bulk, and also to raise material to be ground and distribute it among the mess of grinding bodies-in such manner that a greater output of groimd 1aterial is obtained from a will of given s ze in a given time charged "with such grinding bodies than with the iSlKllB weight of grinding bodies previously used. Furthermore, by making the hollow grinding bodies of helical or'perforated shape as described, they have a greater overall bulk for a givenoweight than hollow grinding bodies such as deshribed in the specification .difany said former upplication Serial l lo. 318%1, and a far greater overall bull; iiora given weight, as compared with solid metal cylinders, each having tne same areaof grinding surface, sd that the Volume or hull: of the load, composed of cement or other material to be ground and grinding bodies, in the mill will be increased as compared with a load comprising the same -weight of cement or other material and grinding bodies of either of the other forms referred to, with the result that not onlywill the output of the mill be considerably in creased but the power required to drive the mill and its load will be decreased.

What I claim is l. The combination with a. tube mill of a number of loose freely movable hollow grinding bodies each made of a length that is equal to a "traction only of the radius of masses the mill but is oi greater length than diameter and has in its peripheral surface a plurality of holes the width or diameter of each of which is less than the width of adjacent portions of the said peripheral surface.

2. The combination with a tube mill of a number of loose freely movable hollow grinding bodies each made of a length that is equal to a fraction only of the radius of the mill but is of greater length than diameter and has a plurality of holes extending completely through its wall, the width or diameter of each hole being less than the width of adjacent portions of the peripheral surface of said wall.

3. The combination with a tube mill of a number of loose freely movable hollow grinding bodies each made of a length that is equal to a fraction only of the radius of the mill but is of greater length than diamcter and has a plurality of elongated holes extending partly, around and completely through its peripheral Wall.

4. The combination with a tube mill of a number of loose freely movable hollow grinding bodies of uniform external cross sectional dimensions throughout their length, eachof said bodies being made of a length that is equal to a fraction only of the radius of the mill but is of greater length than diameter and having a plurality of holes extending through its peripheral wall at an angle to the open ended hole extending centrally and longitudinally through the longest dimension of the body.

5. The combination with a tube mill of number of loose freely movable hollow grinding bodies of uniform cross section throughout their length, each of said bodies being made of a length that is equal to a fraction only of the radius of the mill but is of greater length than diameter and consists of a tube of sheet material divided longitudinally and having holes extending through its wall.

6. The combination with a tube mill of a number of loose freely movable hollow cylindrical grinding bodies each made 01 a length that is equal to a fraction only of the radius of the mill but is of greater length than diameter and consists of a lon- 8. The combination with tube'mill of tmlly and longlt-mlinally through the lon a number of loose freely movable hollow est dimension of the body.

grimling bodies each made of a, length that Signed at London, Englanfi, this 4 clay is equal to a fraction only of the radius of of June 1913.

the will but of greater length than diameter 1 T7 r T HT T and of cylindrical shape both externally and M ILLEAM 1* internally and having a plurality of holes Ylitnesses:

extending through its peripheral Wall at an CYRIL U NDERLAU,

angle to the open ended hole extending cen O. J. WORTH. 

